Relief-valve



L. DQSHAW. Relief Valve.

No. 230,828. Patented-Aug. 3,- 1880.

l-'. PETERS, PHOTO-LITHOGRAPHER. wAsHxNGToN. D C.

UNITED STATES PATENT trice,

LORING D. SHAW, OF BOSTON, MASSACHUSETTS.

RELIEF-VALVE.

SPECIFICATION forming part of Letters Patent No. 230,828, dated August 3, 1880.

` Application filed October 4,1879.

To all whom 'it may concern:

Be it known that I, LORING D. SHAW, ot' Boston, county ot' Suffolk, and State of Massa chusctts, have invented certain new and useful Improvements in Automatic Relief-Valves; and I do hereby declare that the following is aiull, clear, and exact description thereof, which will enable others skilled in the art to which it pertains to make and use the same, reference beinghad to the accompanying drawings, and to the letters thereon, which form a part of this specification.

My invention relates to improvements in automatic relief apparatus, and is to be attached to steam fire-engines and steam tire-pumps, and is for the purpose otl preventing the bursting ot' re-hose if the pressure be. unduly iucreased therein, and is used in connection with stop-cock or cut-off nozzle, so that the hosemen or pipemen can at any time instantly shut ofi' the flow et' water at the pipe without injury to the engine or bursting the hose, by which means it gives them absolute cont-rol of the amount ot' water thrown'into the building.

rIhis my .invention is also useful for the Holly system ot' Waterworks for tire purposes. I

It' consists in the combination ot' a cylinder of two different diameters, with its induction and delivery passages, and provided with movable pistons connected together and adjustable by a hand-screw, with a double-acting piston-valve.

It tina-Il v consists in the particular construction and arrangement of the independent movable pistons and valve, situated one within the other, and moved automatically by theaction ot the increased or diminished pressure ofthe water on the hose.

In thedrawi'ngs, Figure l represents longitudinal section. Fig. 2 represents longitudinal section of movable pistons and valve enlarged, in order to more fully explain my in-4 vention.

Inthe accompanying drawings similar lety ters indicate similar parts.

hollow pistonrod c, and movable within the cylinder c a. The induetioirpassage I) is connected with the delivery side ot' the pump, and the delivery-passage c is connected with the induction or suction side.

When pistons d d iall to their lowest position, piston d/ passes below and opens the delivery-passage, by which means it oi'ers a free delivery ot' the water Jfrom the delivery side ot' the pump, through inductionpassage b, cyl inder a, and delivery-passage c, to the suction or induction side ot' pump.

fis an il'ldependcnt hollow adjustablehandscrew to regulate the travel of pistons, so that any desired pressure can be maintained on the hose when the pumps are working and the stop-cock on the hose is closed.

Situated within piston d, Fig. 2, is pressure chamber g, provided with its openings h, and passage through valve-seat lr, and communieating' with valve chamber t'. Valve-chamber t' has its openings l communicating with the space around valve-chamber i and above piston d. lVithin the valve-chamber t' is a doubleacting piston-valve, fm, movable in a vertical direction, and held to its seat by means ot a spiral spring, n, adjustable so as to maintain any desired pressure. Up and into this piston-valve m extends a recess, from which a series of holes or ports, p, communicate with valve-chamber Extending into the above recess is that part ot' the hollow piston-rod that extends up and beyond piston d, and is for the purpose of preventing t-hc tlow of water through hollow piston-rod when the piston-valve is in its seat. When the pistonvalve isin its seat communication is established between space above piston d, valve-chamber t, and ports p, through piston-valve m, hollow piston-rod e, and hollow hand-screw j', to the atmosphere.

Piston d being in area larger than piston d', the pressure of the water coming in contact between them in cylinder a will cause the said pistons to remain in their highest position, and the piston d will cut oit'communication through delivery-passage c.

The operation o t' this valve is as follows: V'Vhen the pressure ot the water in the hose is suddenly increased above what the pistonvalve m is set to regulate, by closing the cut- IOO off nozzle the said piston-valve will be forcedto its highest position, the comnninieation will be cut oft' through ports from above piston d, and the water will be forced through the openings 71 valve-seat 7.1, pressure-chamber g, and openings l to space above piston d, around valve-chamber fi, by which means the pressure of water will be equalized above and below piston d. The pressure on piston d will force pistons d d to their lowest positions, opening delivery-passage c and offering free passage ofthe water from the delivery side to the induction side of the pump.

When the pressure is still more reduced, by again opening the cut-ojt't' nozzle on the hose, and becomes less than the pressure to which piston-valve is set, the spiral spring ct will force said valve to its seat, and the water above piston d will llow through openings l, ports p, piston-valve m, hollow piston-rod e, and hollow hand-screw to the atmosphere. Piston d, being larger than piston d', will cause them to rise to their highest position.

From the above it will be seen that my relief1 apparatus is working perfectly automatically in opening and closing by the action of the increased or diminished pressure of water on the hose.

What I wish to secure by Letters Patent and cla-im isl. In combination with a iire-engine pump, the cylinder o a', having induction-passage b and delivery-passage c, pistons d rl', connected by the hollow piston-rod 0, the said pistons being of diil'iierent areas and movable within the cylinder a a', the hollow adjustingserew 1", pressure-chamberg, with its openings 7L, and valvelchamber i, with its openings Z, and valveseat lr, substantially as set forth.

2. ln combination with a cylinder and its piston, the double-acting piston-valve m, situated within lvalve-chamber i, and provided with portsj, hollow piston-rode, communicating with said ports, the spiral-spring u, and its adjusting-screw o7 substantially as described. 45

LORING D. SHAW.

Attest:

THOMAS 1I. EVANs, Jr., Jos. Il. ALLEN. 

